The Blackmar-Diemer Gambit

Important variations are animated at the bottom of the page.

This is an interesting opening with extreme controversy as to whether or not this is a good opening.  I do not have any experience personally with it, so I will explain what it is and the goals behind it.  The main line goes 1. d4, d5  2. e4, pxp  3. Nc3, Nf6  4. f3, pxp 5. Nxp.

The Blackmar-Diemer Gambit   A B C D E F G H 8   7   6               5                 4               3             2       1

The Gambit is shown to the left.  There are several reasons to this.  One is moving the light bishop to d3 or c4.  This is to launch a quick attack on the kingside.  I think that it is too easy to repel.  It is black's move, and one of his best choices is c6.  This not only prevents a pawn push right away, it prevents the bishop from checking the king if for any reason checking is a good move.  Another reason behind the Blackmar-Diemer Gambit is like the King's Indian Attack.  White can play Bf4 at some point to try and fork the rook.  Once again, it is easily repelled by c6.  It is true that white has an advantage in space and a small lead in development.  Many claim that it is great to end a game in under 25 moves.  I think that the other player has to be pretty dumb for an accomplishment like that.

After black's move 6   A B C D E F G H 8     7   6             5                 4             3             2       1

Let's say that the line continues on 5...c6  6. Bc4.  I think that another good move here is 6...Nbd7.  This prevents an out posted knight on e5.  this is shown on the left.  If they do go 7. Ne5, NxN  8. pxN, Nd7.  This doesn't threaten anything at the moment, but then you prepare to move Nb6 to threaten the bishop and promptly release your own.  Another idea is 6...e6.  This is to pin the c knight and eventually castle out of trouble.  Castling queenside is probably a bad idea in this case because of how open the king is there.  Kingside, however, is safe.  White has many possible threats with the Blackmar-Diemer Gambit, but they seem to be easy to defend.  It is probably not a good idea to try this.  However, I have not had much experience with this.  Some will ardently argue that white is very good